1. Field of the Invention
The present invention relates in general to an ink-jet recording apparatus which performs recording by ejecting ink to a recording medium.
2. Discussion of Related Art
An ink-jet recording apparatus such as an ink-jet printer includes: an ink-jet head in which are formed a multiplicity of nozzles and which includes actuators respectively corresponding to the nozzles; and a driver IC which generates drive signals for driving the actuators. By applying, to the actuators, the drive signals generated by the driver IC, the actuators are driven, whereby ink is ejected from the nozzles for recording images and the like on a recording medium such as a recording sheet.
Representative examples of the actuator include an electrostatic actuator produced by a silicon process and a piezoelectric actuator including a piezoelectric element. Various other actuators utilizing energy transducing principle are also used. In particular, the piezoelectric actuator is widely used for the following reasons: Because the amount of deformation of the piezoelectric actuator is proportional to a voltage applied thereto, it is possible to eject ink droplets of various sizes or volumes by varying the voltage. Further, the piezoelectric actuator permits use of comparatively large sorts of inks.
The actuator, however, has a characteristic that the amount of deformation changes depending upon an environmental temperature. This characteristic is outstanding particularly in the piezoelectric actuator mentioned above. Due to this characteristic, the ejection of the ink may become unstable, causing a risk of deteriorating the print quality. In view of this, there are employed measures for stabilizing the ejection of the ink by changing the waveform and the voltage of the drive signal to be applied to the actuator, for instance. JP-A-2001-1516 discloses a technique to calculate temperature of the actuator based on the waveform of the drive signal of the actuator and correct ejection amount data in accordance with the calculated temperature. The ejection amount data is a basis for the drive signal to be applied to the actuator, and the waveform and the voltage of the drive signal are changed by correcting the ejection amount data.